1. Field of the Invention
This invention relates to acoustic to optical pulse code modulating transducers, and, in particular, to means for directly pulse code modulating an optical carrier with an acoustic signal without the intermediate step of converting the acoustic signal to an electrical signal. Accordingly, it is a general object of this invention to provide new and improved transducers and means of such character.
2. Description of the Prior Art
With the rapid development of communications utilizing a light wave transmitted along an optical fiber, it is desirable to provide transducers which efficiently and conveniently convert information in the form of acoustical signals to modulation on an optical carrier.
Various apparatus of the prior art first convert the acoustic information to an electrical signal. The electrical signal is then used to modulate the optical carrier by modulation of the current drive to, and thus the light level emitted by, the optical carrier source (e.g., diode laser, light emitting diode). In some prior art devices, the electrical signal drives a modulator device external to the optical power source.